Decoder, decoding method, and program distribution medium therefor

摘要

A time domain signal is converted into a frequency domain signal, and an encoded bit stream is provided. A bit stream decomposer decodes bit stream information, and a storage unit temporary stores the information. In accordance with the bit stream information, a spectral expander expands a frequency spectrum quantized inverse by in an inverse quantizer up to an integer multiple of a sampling frequency of the bit stream. A frequency-time domain converter converts the frequency spectrum into a time domain signal. Thereby, harmonics can precisely be implemented with a small amount of processing, and the band can be expanded with less distortion.